view mod_log_events_by_memory/mod_log_events_by_memory.lua @ 5668:ecfd7aece33b

mod_measure_modules: Report module statuses via OpenMetrics Someone in the chat asked about a health check endpoint, which reminded me of mod_http_status, which provides access to module statuses with full details. After that, this idea came about, which seems natural. As noted in the README, it could be used to monitor that critical modules are in fact loaded correctly. As more modules use the status API, the more useful this module and mod_http_status becomes.
author Kim Alvefur <zash@zash.se>
date Fri, 06 Oct 2023 18:34:39 +0200
parents 5fe34e5f9829
children
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module:set_global();

local treshold = module:get_option_number("log_memory_threshold", 20*1024);

function event_wrapper(handlers, event_name, event_data)
	local memory_before = collectgarbage("count")*1024;
	local ret = handlers(event_name, event_data);
	local memory_after = collectgarbage("count")*1024;
	if (memory_after - memory_before) > treshold then
		module:log("warn", "Memory increased by %g bytes while processing event '%s'", (memory_after - memory_before), event_name);
	end
	return ret;
end

local http_events = require "net.http.server"._events;
module:wrap_object_event(http_events, false, event_wrapper);

module:wrap_event(false, event_wrapper);
function module.add_host(module)
	module:wrap_event(false, event_wrapper);
end